/*
 * contrib/btree_gist/btree_numeric.c
 */
#include "postgres.h"
#include "knl/knl_variable.h"

#include "btree_gist.h"

#include <math.h>
#include <float.h>

#include "btree_utils_var.h"
#include "utils/builtins.h"
#include "utils/numeric.h"
#include "utils/numeric_gs.h"
#include "utils/rel.h"
#include "utils/rel_gs.h"

/*
** Bytea ops
*/
PG_FUNCTION_INFO_V1(gbt_numeric_compress);
PG_FUNCTION_INFO_V1(gbt_numeric_union);
PG_FUNCTION_INFO_V1(gbt_numeric_picksplit);
PG_FUNCTION_INFO_V1(gbt_numeric_consistent);
PG_FUNCTION_INFO_V1(gbt_numeric_penalty);
PG_FUNCTION_INFO_V1(gbt_numeric_same);

extern "C" Datum gbt_numeric_compress(PG_FUNCTION_ARGS);
extern "C" Datum gbt_numeric_union(PG_FUNCTION_ARGS);
extern "C" Datum gbt_numeric_picksplit(PG_FUNCTION_ARGS);
extern "C" Datum gbt_numeric_consistent(PG_FUNCTION_ARGS);
extern "C" Datum gbt_numeric_penalty(PG_FUNCTION_ARGS);
extern "C" Datum gbt_numeric_same(PG_FUNCTION_ARGS);

/* define for comparison */

static bool gbt_numeric_gt(const void* a, const void* b, Oid collation)
{
    return DatumGetBool(DirectFunctionCall2(numeric_gt, PointerGetDatum(a), PointerGetDatum(b)));
}

static bool gbt_numeric_ge(const void* a, const void* b, Oid collation)
{
    return DatumGetBool(DirectFunctionCall2(numeric_ge, PointerGetDatum(a), PointerGetDatum(b)));
}

static bool gbt_numeric_eq(const void* a, const void* b, Oid collation)
{
    return DatumGetBool(DirectFunctionCall2(numeric_eq, PointerGetDatum(a), PointerGetDatum(b)));
}

static bool gbt_numeric_le(const void* a, const void* b, Oid collation)
{
    return DatumGetBool(DirectFunctionCall2(numeric_le, PointerGetDatum(a), PointerGetDatum(b)));
}

static bool gbt_numeric_lt(const void* a, const void* b, Oid collation)
{
    return DatumGetBool(DirectFunctionCall2(numeric_lt, PointerGetDatum(a), PointerGetDatum(b)));
}

static int32 gbt_numeric_cmp(const void* a, const void* b, Oid collation)
{
    return DatumGetInt32(DirectFunctionCall2(numeric_cmp, PointerGetDatum(a), PointerGetDatum(b)));
}

static const gbtree_vinfo tinfo = {gbt_t_numeric,
    0,
    FALSE,
    gbt_numeric_gt,
    gbt_numeric_ge,
    gbt_numeric_eq,
    gbt_numeric_le,
    gbt_numeric_lt,
    gbt_numeric_cmp,
    NULL};

/**************************************************
 * Text ops
 **************************************************/

Datum gbt_numeric_compress(PG_FUNCTION_ARGS)
{
    GISTENTRY* entry = (GISTENTRY*)PG_GETARG_POINTER(0);

    PG_RETURN_POINTER(gbt_var_compress(entry, &tinfo));
}

Datum gbt_numeric_consistent(PG_FUNCTION_ARGS)
{
    GISTENTRY* entry = (GISTENTRY*)PG_GETARG_POINTER(0);
    void* query = (void*)DatumGetNumeric(PG_GETARG_DATUM(1));
    StrategyNumber strategy = (StrategyNumber)PG_GETARG_UINT16(2);

    bool* recheck = (bool*)PG_GETARG_POINTER(4);
    bool retval = false;
    GBT_VARKEY* key = (GBT_VARKEY*)DatumGetPointer(entry->key);
    GBT_VARKEY_R r = gbt_var_key_readable(key);

    /* All cases served by this function are exact */
    *recheck = false;

    retval = gbt_var_consistent(&r, query, strategy, PG_GET_COLLATION(), GIST_LEAF(entry), &tinfo);
    PG_RETURN_BOOL(retval);
}

Datum gbt_numeric_union(PG_FUNCTION_ARGS)
{
    GistEntryVector* entryvec = (GistEntryVector*)PG_GETARG_POINTER(0);
    int32* size = (int*)PG_GETARG_POINTER(1);

    PG_RETURN_POINTER(gbt_var_union(entryvec, size, PG_GET_COLLATION(), &tinfo));
}

Datum gbt_numeric_same(PG_FUNCTION_ARGS)
{
    Datum d1 = PG_GETARG_DATUM(0);
    Datum d2 = PG_GETARG_DATUM(1);
    bool* result = (bool*)PG_GETARG_POINTER(2);

    *result = gbt_var_same(d1, d2, PG_GET_COLLATION(), &tinfo);
    PG_RETURN_POINTER(result);
}

Datum gbt_numeric_penalty(PG_FUNCTION_ARGS)
{
    GISTENTRY* o = (GISTENTRY*)PG_GETARG_POINTER(0);
    GISTENTRY* n = (GISTENTRY*)PG_GETARG_POINTER(1);
    float* result = (float*)PG_GETARG_POINTER(2);

    Numeric us, os, ds;

    GBT_VARKEY* org = (GBT_VARKEY*)DatumGetPointer(o->key);
    GBT_VARKEY* newe = (GBT_VARKEY*)DatumGetPointer(n->key);
    Datum uni;
    GBT_VARKEY_R rk, ok, uk;

    rk = gbt_var_key_readable(org);
    uni = PointerGetDatum(gbt_var_key_copy(&rk, TRUE));
    gbt_var_bin_union(&uni, newe, PG_GET_COLLATION(), &tinfo);
    ok = gbt_var_key_readable(org);
    uk = gbt_var_key_readable((GBT_VARKEY*)DatumGetPointer(uni));

    us = DatumGetNumeric(DirectFunctionCall2(numeric_sub, PointerGetDatum(uk.upper), PointerGetDatum(uk.lower)));

    os = DatumGetNumeric(DirectFunctionCall2(numeric_sub, PointerGetDatum(ok.upper), PointerGetDatum(ok.lower)));

    ds = DatumGetNumeric(DirectFunctionCall2(numeric_sub, NumericGetDatum(us), NumericGetDatum(os)));

    if (numeric_is_nan(us)) {
        if (numeric_is_nan(os))
            *result = 0.0;
        else
            *result = 1.0;
    } else {
        Numeric nul = DatumGetNumeric(DirectFunctionCall1(int4_numeric, Int32GetDatum(0)));

        *result = 0.0;

        if (DirectFunctionCall2(numeric_gt, NumericGetDatum(ds), NumericGetDatum(nul))) {
            *result += FLT_MIN;
            os = DatumGetNumeric(DirectFunctionCall2(numeric_div, NumericGetDatum(ds), NumericGetDatum(us)));
            *result += (float4)DatumGetFloat8(DirectFunctionCall1(numeric_float8_no_overflow, NumericGetDatum(os)));
        }
    }

    if (*result > 0)
        *result *= (FLT_MAX / (((GISTENTRY*)PG_GETARG_POINTER(0))->rel->rd_att->natts + 1));

    PG_RETURN_POINTER(result);
}

Datum gbt_numeric_picksplit(PG_FUNCTION_ARGS)
{
    GistEntryVector* entryvec = (GistEntryVector*)PG_GETARG_POINTER(0);
    GIST_SPLITVEC* v = (GIST_SPLITVEC*)PG_GETARG_POINTER(1);

    gbt_var_picksplit(entryvec, v, PG_GET_COLLATION(), &tinfo);
    PG_RETURN_POINTER(v);
}
